Sound discriminator alarm system

ABSTRACT

The disclosure relates to a security system for detecting intruders wherein sound frequencies introduced by the intruder or the like can be detected apart from normal environmental noise to provide an alarm. The system discriminates between normal noise or environmental noise and intruder-produced noise by use of a filter as well as a time delay to eliminate response of the system due to transients and the like.

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Eakin Aug. 8, 1972 [54] SOUND DISCRIMINATOR ALARM 3,158,850 ll/l964 Poznanski ..340/261X SYSTEM Inventor:

3244, Jackson, Miss. 39207 Filed: June 30, 1969 Related US. Application Data 4, 1968, abandoned.

Field of Search ..340/258, 261, 258 R, 258 D References Cited UNITED STATES PATENTS 11/1970 Burney ..340/258 R X Horace D. Eakln, PO. Box No.

3,261,909 7/1966 Stetten et a1 Primary Examinef-John Caldwell Assistant Examiner-Michael Slobasky Attorney-Stevens, Davis, Miller & Mosher 571 I ABSTRACT 1 The disclosure relates to a security system for detect- Continuation-in-part of Ser. No. 757,228, Sept.

ing intruders wherein sound frequencies introduced by the intruder or the like can be detected apart from normal environmental noise to provide an alarm. The system discriminates between normal noise or environmental noise and intruder-produced noise by use of a filter as well as a time delay to eliminate response of thE s'ys'tem due to transients and the like.

18 Claims, 2 Drawing Figures X l AUDIO. Vi TRANSDUCER AUDIO l9 l rmusnucsa AUDIO TRANSDUCER P l" D E F T0 AUDIO RANSDUCERS O I I La. v t b This application is a continuation-impart of my copending application, Ser. No. 757,228, filed Sept. 4, 1968 for Sound Discriminator Alarm System, and now abandoned.

This invention relates to an alarm system utilizing sound discrimination and, more specifically, to an alarm system for detecting intruder produced noise apart from existing environmental noise and electronically produced noise to indicate an alarm condition.

The prior art has disclosed sound actuated alarm systems responsive only to particular types of sound to provide the alarm indication. The major difficulty encountered in the prior art alarm systems of this type has been their inability to adequately differentiate between the constant noise that is produced by the environment under protection and transient noises of various types which are produced in electronic alarm systems and which also give rise to false alarm signals.

In accordance with the present invention, the above described problems of. the prior art are overcome wherein all types of constant noise present in the environment as well as transient noises produced by the electronic systems are rejected to reduce false alarm conditions to a minimum. The above is provided by the use of an electronic filter in the output circuit of the audio transducers to removethe electrical noise of most varieties. In addition, a sound discriminator is provided which rejects all constant noise present which has a db level sufficient to activate the alarm. The I remaining sounds are the intermittent noises produced by the existence of the alarm condition. The system includes a stepping relay in the sound discriminator to control the number of different types of noise required vention will immediately become apparent to those skilled in the art after consideration of the following specific preferred embodiment of the invention which is provided by way of example and not by way of limitation wherein:

FIGS. 1A and 1B are a circuit diagram of the preferred embodiment of the invention.

Referring now to the drawings, there is shown a schematic diagram of the preferred embodiment of the sound discriminator alarm system of the present invention. The system includes the plurality of outlying audio transducers 1, 3 and 5, each connected to an amplifier 7. As an alternative, each of the transducers could be 0.16 millihenry and would be connected to reference potential from the junction of the capacitors. The output of the filter is coupled by means of a jack or otherwise to a transformer 11 where the signal representing the sound which has been picked up by theaudio trans ducers, amplifiedand filtered electronically to remove hum and the like, is stepped up in voltage. The output from the secondary of the transformer is full-wave rectified in the rectifier 13 to provide a DC. equivalent of the sounds picked up by the audio transducers.

The output of rectifier 13 is fed in parallel to a pair of relays 15 and 17 to energize the coils thereof. The contact 19 of relay 17 is normally open and, upon reception of the signal, closes the contact 19 and completes the circuit to contacts 21 and 23 of relay 25. Contact 23 is coupled to the coil of relay 27 and causes same to be energized by completion of the circuit to the voltage source 33 since contact 21 is coupled to the source 33 already. Thereby, contacts 29 and 31 of relay 27, which are normally open, will be closed due to energization of the coil of relay 27.

The closing of contact 29 causes current to pass from the AC. source 33 through the-motor 35 and back to source 33 since contact 29 is coupled to the source 33. The switch 97 is assumed to have been initially closed. The motor 35 will thereby be started and cause a cycling device 37 in the form of a plurality of cams or wheels with pins thereon, etc., one associated with each of contacts of switches 39, 41, 43 and 45, to be operated and operate the switches 39, 41, 43 and 45 in a manner to be described in detail hereinbelow. The 7 motor 35 is a synchronous motor operating at 1 rpm associated cam and will remain closed for the full one minute period from time t equals 0 to time t equals 60 seconds. Closing of contact 39 completes a circuit through motor 35 and thereby causes the motor to continueto be energized after relay 27 is de-energized. Contact 39 is therefore part of a hold circuit for the synchronous motor 35 and maintains operation of motor 35 for the full one minute period. At this point,

from-motor 35 due to the hold circuit of motor 35 connected to its own separate amplifier. The output of being in operation. After the motor 35 has been operating for one second, a second member in cycling device 37 will open the contact 43 and will break the original starting circuit to motor 35 by breaking the hold circuit to relay 27 which was previously completed, relay 17 now being de-energized. The motor 35, however, will continue to rotate due to the closing of the contact 39.

At time t equals 2 seconds after the start of the motor 35, normally open contact 41 will close due to the third cam or the like in the cycling device 37. The contact 41 will remain closed from time t equals 2 seconds to time t equals 58 seconds. The closure of the contact 41 causes relay 47 to be energized and closes switch 98. Thereby the windings of relays 25 and 49 are energized and start the operating mode. This will cause the switches 21 and 23 of relay 25 to contact the contacts 51 and 53 respectively. This operation causes the relay 25 to complete a circuit in conjunction with contact 19 via contacts 51 and 53 which parallels the circuit through switch 55 to establish a hold circuit for the synchronous motor 57. Switch 55 therefore establishes a hold circuit for the synchronous motor 57.

If a sufficient signal be present at the output of 'the rectifier 13 and at relay 17, contact 19 will be closedas previously stated and the closing of normally open con-, tact 19, as previously stated, completes a circuit to the synchronous motor 57 to start same through contacts 51 and 53 of relay 25. Synchronous motor 57 drives a ing this period of 56 seconds, there is not sufficientnoise to advance stepping relay 65 the required number of steps, (to be explained hereinbelow) to establish a hold :circuit in relay 69, which is the alarm relay, relay 25, 47 and 49 will return to normal and D.C. power will be'applied to the homing circuit of stepping relay 65 to neutralize same and return the stopping contact 7 member 67 thereof to the home position two-second cam 59 or other equivalent device having a termittent, i.e., for less than I second, the motor 57 will switch 61 'which is in series with the normally closed 7 contact 63 of relay 15 will close due to action of cam pin 107, contact 63 being closed because the noise is no longer present. This will form a complete circuit to stepping relay 65 from the rectifier 81, contact 95, switches 61, 63 and 127, relay 65 and contact 99 and provide a pulse to relay 65, since the circuit is completed only during the period that cam pin 107 closes switch 61. This causes the stepping relay 65 to advance one position by the counterclockwise rotation of the wiper 67 thereof one step. This will be explained in more detail hereinbelow.

At the end of two seconds, synchronous motor 57 will stop because switch 55 will be open due to the completion of the cycle by cam 59.

If we now consider that constant noise is present and a constant output is provided to the relays 15 and 17,

' synchronous motor 57 will continue to run and, at the power is obtained by rectifying the A.C. power obtained from source 33 in full wave rectifier 81, the D.C. output of the rectifier being filtered by filter 83.

lnterposed between relay 65 coil and the D.C. power supply are relay contacts 103 and 105 of relay 101.

Relay 101 has A.C. power thereacross constantly to 'maintain the arm 109 on contact 103 and arm 111 on contact 105. In this manner, in the event of a loss of power from source 33 the power from rectifier 81 and filter 83 cannot be transmitted to the coil of relay 65, thereby preventing charge stored in the capacitors 0f filter 83 from being transmitted to relay 65 and advancin g same possibly to the alarm condition.

The synchronous motor 35 has a 60-second cycle as explained hereinabove. Two seconds after the motor The homing circuit of stepping relay 65 is a vibratortype circuit, the contacts of which are operated by relay 65 along with the wiper member 67. When D.C. power via rectifier 81 is applied to the homing circuit of relay'65, the wiper, member 67 will move to the home position. This is provided when relay 49 is de-energized. Current will pass from rectifier 81, through contact 103 and switch 109 to switch 119 and contact 1 15, then through switch 93 to relay 65 and back to rectifier 81 via switch 91, contact 113, switch 117, contact 105 and switch 111. When wiper member 67 reaches the home position due to the constant D.C. fed to relay 65, a cam positioned thereon (not shown) or the like will open one'or both of the sets of contacts 91 or 93,

; thereby removing power from the homing circuit. Circuits of this type are known in the art. v

The hold circuit is established by first setting a variable position switch 71 to any one of ten positions. This setting will determine the number of steps through which the stepping contact member 67 must pass beyond the home position before an alarm condition is provided to the alarm relay 69. It can be seen that sufficient stepping of contact member 67 completes a circuit from A.C. source 33 through member 85, member 67 and relay 69 to cause contact 75 to open the circuit with contact 77 and energize alarm 73. Further, the contact is closed for 54 seconds from time t equals 3 seconds to time 1 equals 57 seconds and 5 permits the alarm relay to be operated only when contact 45 is closed. Therefore, energization. of alarm relay 69 causes contact 87 to engage pin 89 in addition to operation of the alarm. This forms a holding circuit for relay 69 through contact 45 until contact 45 is opened after 57 seconds of the operation and allows the alarm 73 to continue to operate until contact 45 is again opened. In this manner, the alarm relay 69 cannot be tripped during switching from start to operating mode or in switching back to neutralized position since contact 41 is not opened until time t equals 58 seconds at which time everything is shut off. At the end of 1 minute from time equals 0, switch 39 opens and the motor 35 stops. Relay 69 could, of course, be a locking relay which locks when placed in the alarm condition until manually reset.

. The circuit including relays 125, 129 and 131,.along with switches 121 and 123, associated with the cam pin I 107, are included to avoid the possibility of advancing.

' the stepping relay at the end of a noise duration pin 107 will close the switch 121. This will have no effect at this time because one side of switch 121 is connected to a normally open contact of relay 131. As the cam 59 and cam pin 107 continue their rotation, the cam pin will close the switch 61 after one second as described above. The stepping relay 65 will not be advanced at this time because the switch 63 will be open due to energization to the relay 15. After another half second of rotation, the cam pin 107 will close the switch 123. This will complete the circuit through relay 131 and energize the coil thereof to circuit for relay 1'31.

Since constant noise is being provided, the relays and 17 will continue to be energized and will not permit the cam 59 to stop when the switch 55 is opened by the completion of the cycle. Cam 59 will therefore start its second rotation and close switch 121. With the contact provide a holding 141 now being connected to the switch member 143,

gized to start motor 57 and cause rotation of cam 59 as explained above. The closing of switch 121 will have no effect as stated in the prior situation. Cam pin 107, continuing its rotation, will then close switch 61 and, through switch 63, which is normally closed and is closed at this time (it being assumed the noise is intermittent), will cause an advance of stepping relay 65 in the manner described hereinabove. The cam 59 will continue its rotation and cam pin 107 will now close switch 123. This will energize and establish a hold circuit in relay-131 as described above. Cam 59 will continue its rotation to the end of the cycle and will stop I and switch 55 opens to remove the power to relay 131 since no power is now being fed to the motor 57 from which the power for energizing the relays 125, 129 and 131 is obtained.

The system also includes an alternative circuit for picking up noise at outlying regions, the circuit to be 7 1 described being used to overcome the problems caused by long runs of cable and the use of a very large number of audio transducers. The outputs of the audio transdu- 50 cers are fed to a radio frequency filter 139 which filters out any RF that may be picked up by the audio transducers and long runs of cable. The output of the filter is fed through an input transformer 137 to an amplifier 135. Amplifier 135 is used to amplify the various sounds picked up by the audio transducers and serves as a voltage amplifier to excite or control the amplifier 7 in standard manner. The output of the amplifier 135 is fed to the amplifier 7 through a line to line transformer 133 which provides loose coupling to amplifier 7. The degreeof coupling may be varied by the taps provided on the line to line transformer. The purpose of the loose coupling between amplifier 135 and amplifier 7 is to eliminate cumulative background noise where a great number of speakers are used. With the use of this configuration it is possible to vary the gain of amplifier 135 to almost any desired degree without exciting or controlling amplifier 7.'The abnormal or transit noises from inside or outside a building or area being monitored will be amplified by the amplifier 135 and applied to the input circuit of the amplifier 7 to excite or control same It can therefore be seen that the alarm system described hereinabove is not operative in response to electrical transients and furthermore is not operative for constant level background noise signals. The system will operate only in response to abnormal intermittent noise which appears in sufficient quantity during a predetermined time period to provide an alarm condition and set off the alarm 73.

Though the invention has been described with respect to a specific preferred embodiment thereof, many variations and modifications thereof will immediately become apparent to those skilled in the art. It is therefore-the intention that the appended claims be interpreted as broadly as possible in view of the prior art to include all such variations and modifications.

What is claimed is:

1. A sound discriminator for a security system which comprises first means responsive to frequencies of predetermined frequency bank to provide an indication thereof at an arbitrary starting time, second means responsive to the absence of frequencies of said predetermined frequency band during a predetermined time period subsequent to said starting time for providing an indication thereof, third means responsive to a predetermined simultaneous indication from said first and second means for providing an indication thereof, and fourth means responsive to a predetermined number of separate indications by said third means fo providing an alarm indication. r

2. A sound discriminator as set forth in claim 1 wherein said first means includes a circuit closed by a relay responsive to frequencies of predetermined frequency band and said second means includes a second circuit which is closed in response to the absence of frequencies of said predetermined band, further including clock means responsive to said first means for priming the closing of said second circuit a predetermined time after said sensing of said frequencies of said predetermined band by said first means.

3. A sound discriminator as set forth in claim 1 wherein said third means includes a stepping switch.

4. A sound discriminator as set forth in claim 2 wherein said third means includes a stepping switch.

5. 'A sound discriminator as set forth in claim 3 wherein said fourthmeans includes means responsive to a predetermined step of said stepping switch.

6. A sound discriminator as set forth in claim 4 wherein said fourth means includes means responsive to a predetermined step of said stepping switch.

7. A sound discriminator as set forth in claim 5 further including second timing means actuated by said first means for resetting said third means after a second predetermined time.

8. A sound discriminator as set forth in claim 6 further including second timing means actuated by said first means for resetting said third means after a second predetermined time.

9. A sound discriminator as set forth in claim 1 wherein said first means includes a filter having a pass band of predetermined frequency range.

further including sixth means responsive to operation of said first means for normally operating said third means, said fifth means being responsive to the presence of said frequencies of predetennined frequency bandat said still later predetermined time for in hibiting'operation'of said third means.

16. A sound discriminator as set forth in claim 12 I further including sixth means responsive to operation cy band at said later predetennined time and at a third still later predetermined time for inhibiting operation of said third means. i j" 13. A sound discriminator as set forth in claim7 further including fifth means responsive to the presence of said frequencies of predetermined frequency band at said later predetermined time and at a third still later predetermined time for inhibiting operation of said third means.

14. A sound discriminator as set forth in claim 8 of said first means for normally operating said third means, said fifth mears being responsive to the I presence of said frequencies of predetermined frequency band at said still later predetermined time for inhibiting operation of said third means.

17. A sound discriminator as set forth in claim 13 further including sixth means responsive to operation I of said first means for normally operating said third further including fifth means responsive to the 1 presence of said frequencies of predetermined frequency band at said later predetermined time and at a third still later predetermined time for inhibiting operation of said third means.

15. A sound discriminator as set forth in claim 11 means, said fifth means being responsive to the presence of said frequenciesv of predetermined frequency band at said still later predetermined time for inhibiting operation of said third means.

18. A sound discriminator as set forth in claim 14 further including sixth means responsive to operation of said first means for normally operating said third means, said fifth means being responsive to the presence of said frequencies .of predetermined frequency band at said still later predetermined time for inhibiting operation of said third means.

t t a a s 

1. A sound discriminator for a security system which comprises first means responsive to frequencies of predetermined frequency bank to provide an indication thereof at an arbitrary starting time, second means responsive to the absence of frequencies of said predetermined frequency band during a predetermined time period subsequent to said starting time for providing an indication thereof, third means responsive to a predetermined simultaneous indication from said first and second means for providing an indication thereof, and fourth means responsive to a predetermined number of separate indications by said third means for providing an alarm indication.
 2. A sound discriminator as set forth in claim 1 wherein said firSt means includes a circuit closed by a relay responsive to frequencies of predetermined frequency band and said second means includes a second circuit which is closed in response to the absence of frequencies of said predetermined band, further including clock means responsive to said first means for priming the closing of said second circuit a predetermined time after said sensing of said frequencies of said predetermined band by said first means.
 3. A sound discriminator as set forth in claim 1 wherein said third means includes a stepping switch.
 4. A sound discriminator as set forth in claim 2 wherein said third means includes a stepping switch.
 5. A sound discriminator as set forth in claim 3 wherein said fourth means includes means responsive to a predetermined step of said stepping switch.
 6. A sound discriminator as set forth in claim 4 wherein said fourth means includes means responsive to a predetermined step of said stepping switch.
 7. A sound discriminator as set forth in claim 5 further including second timing means actuated by said first means for resetting said third means after a second predetermined time.
 8. A sound discriminator as set forth in claim 6 further including second timing means actuated by said first means for resetting said third means after a second predetermined time.
 9. A sound discriminator as set forth in claim 1 wherein said first means includes a filter having a pass band of predetermined frequency range.
 10. A sound discriminator as set forth in claim 8 wherein said first means includes a filter having a pass band of predetermined frequency range.
 11. A sound discriminator as set forth in claim 1 further including fifth means responsive to the presence of said frequencies of predetermined frequency band at said later predetermined time and at a third still later predetermined time for inhibiting operation of said third means.
 12. A sound discriminator as set forth in claim 2 further including fifth means responsive to the presence of said frequencies of predetermined frequency band at said later predetermined time and at a third still later predetermined time for inhibiting operation of said third means.
 13. A sound discriminator as set forth in claim 7 further including fifth means responsive to the presence of said frequencies of predetermined frequency band at said later predetermined time and at a third still later predetermined time for inhibiting operation of said third means.
 14. A sound discriminator as set forth in claim 8 further including fifth means responsive to the presence of said frequencies of predetermined frequency band at said later predetermined time and at a third still later predetermined time for inhibiting operation of said third means.
 15. A sound discriminator as set forth in claim 11 further including sixth means responsive to operation of said first means for normally operating said third means, said fifth means being responsive to the presence of said frequencies of predetermined frequency band at said still later predetermined time for inhibiting operation of said third means.
 16. A sound discriminator as set forth in claim 12 further including sixth means responsive to operation of said first means for normally operating said third means, said fifth means being responsive to the presence of said frequencies of predetermined frequency band at said still later predetermined time for inhibiting operation of said third means.
 17. A sound discriminator as set forth in claim 13 further including sixth means responsive to operation of said first means for normally operating said third means, said fifth means being responsive to the presence of said frequencies of predetermined frequency band at said still later predetermined time for inhibiting operation of said third means.
 18. A sound discriminator as set forth in claim 14 further including sixth means responsive to operation of said first means for normally operating said third means, said fifth means beiNg responsive to the presence of said frequencies of predetermined frequency band at said still later predetermined time for inhibiting operation of said third means. 